Specify defaults for variables

[dkastl]

Currently it seems to be required to have an .env in place with environment variables set.

WARN[0000] The "GEM_PG_VERSION" variable is not set. Defaulting to a blank string. 
WARN[0000] The "SMTP_PASSWORD" variable is not set. Defaulting to a blank string. 
WARN[0000] The "SMTP_AUTHENTICATION" variable is not set. Defaulting to a blank string. 
WARN[0000] The "GEM_PG_VERSION" variable is not set. Defaulting to a blank string. 
WARN[0000] The "SMTP_ADDRESS" variable is not set. Defaulting to a blank string. 
WARN[0000] The "SMTP_PORT" variable is not set. Defaulting to a blank string. 
WARN[0000] The "POSTGRES_PASSWORD" variable is not set. Defaulting to a blank string. 
WARN[0000] The "POSTGRES_USER" variable is not set. Defaulting to a blank string. 
WARN[0000] The "POSTGRES_DB" variable is not set. Defaulting to a blank string. 
WARN[0000] The "SMTP_DOMAIN" variable is not set. Defaulting to a blank string. 
WARN[0000] The "SMTP_USER_NAME" variable is not set. Defaulting to a blank string. 
WARN[0000] The "SMTP_ENABLE_STARTTLS_AUTO" variable is not set. Defaulting to a blank string. 
WARN[0000] The "POSTGRES_USER" variable is not set. Defaulting to a blank string. 
WARN[0000] The "POSTGRES_PASSWORD" variable is not set. Defaulting to a blank string. 
WARN[0000] The "POSTGRES_DB" variable is not set. Defaulting to a blank string. 

If possible, it might be nice to have a default value for each variable.

[sanak]

@dkastl I added .env.example for the default value and mentioned it on README.md - Quick start section.

• b82c9d4#diff-a3046da0d15a27e89f2afe639b25748a7ad4d9290af3e7b1b6c1a5533c8f0a8c
• https://github.com/gtt-project/docker-gtt/blob/main/README.md#quick-start

[dkastl]

Yes, I know this. I just saw also this line https://github.com/gtt-project/docker-gtt/blob/main/Dockerfile#L74
And it's also specified in .env. So maybe we could have fallback values if not set in .env

[sanak]

Okay, but I guess that .env variables may be increased for future, so duplicating both side may cost.

[dkastl]

Not sure if there would be a way to have another default.env file and values are taken from there when not provided by .env. But just an idea.